Lathe-dog.



W. AVERY.

LATHE DOG.

APPLICATION FILED JAN- 3. 1914.

Patented Feb. '15, 1916.

\X/PFHEEEEE WILLIAM AVERY, OF FOXBORO, MASSACHUSETTS.

LATHE-Doe.

Specification of Letters Patent.

Patented Feb. 15, 1916.

To all whom it may concern: A

Be it known that I, WVILLIAM AVERY, of Foxboro, in the county of Norfolkand State of Massachusetts, have invented certain new and usefulImprovements in Lathe-Dogs, of which the following is a specification.

This invention relates to an improvement in lathe dogs.

The object of the invention is to provide a lathe dog which will handleany shape of stock, which can be readily clamped and released while thelathe is in motion, and which will adjust itself to irregularitieswithout bringing side strain on the lathe center. 1

With the above object in view, the invention consists in the lathe doghereinafter 'described and particularly defined in the claim.

The invention will be readily understood from an inspection of theaccompanying drawing, in which-- Figure 1 is a front elevation of anillustrative embodiment of the invention, with parts broken away, andFig. 2 is a vertical section taken on the line 2-2 in Fig. 1.

As illustrated in the drawing, the dog comprises a supporting member inthe form of a collar 10, which is adapted to rotatably fit very looselya stationary member or sleeve 12, the latter being internally threadedto fit the spindle of a lathe, and it may be provided with a center 13.The collar 10 is secured to the sleeve 12 by means of set screws 14,which are adapted to enter holes 16 in said sleeve. These screws 14 donot bottom, neither do they touch the sides of the holes 16. There is aclear space of '5 of an inch all around between sleeve 12 and the collar10. Acting in these spaces it becomes a floating dog, and automaticallyadjusts itself to the centers.

A pair of clamping jaws 20, 21 are provided, having cylindrical portions22, 23,

which are pivotally mounted on pins 24, 25,

and held by said pins between an annular plate or ring 26 and a flange28 on the collar 10. The pins 24, 25 are provided with heads 29 on oneend, which bear against the outside of the ring 26, and each pin isprovided on the other end with a washer 30 and a cotter pin 31. The ring26 is also secured to the flange 28 by means of screws 32.-

The cylindrical portions 22, 23 of the jaws are provided with gear teeth34 over a portion of their peripheral faces, and these teeth mesh'withgear teeth 36 on the inner peripheral face of a ring 38. This ring isprovided with an inner flange or web 40, which fits between the ring orplate 26 and the flange'28, and the outer faces of the ring 38 areknurled or roughened to enable said ring to be more readily held by thehand of the operator while clamping and releasing a piece of work.

The jaws 20, 21 are provided with arouate work-engaging faces 42, 43,which are provided with teeth 44, or otherwise roughened-to engage thework. These faces are eccentric with respect to the pivotal centers ofthe jaws, and approach the work or recede therefrom simultaneously whenthe ring 38 is rotated relatively to the flange 28.

By the construction above set forth it will be observed that acomparatively short I movement of the ring 38 will cause a considerablemovement of the clamping jaws. The dog will clamp and center any shapeof stock, such as round, square, oblong or other polygonalcross-section, and it can be closed upon the work or released therefromwhen the lathe is in motion, thus saving time. i

The dog is also floating as it is freely rotatable about the sleeve 12,andis constructed so that it will adjust itself to irregularities.without bringing any lateral or side strain upon the lathe center, whichis also a very important feature. It is also adapted for use in holdinga piece of material when a taper is to be turned thereon with thetailstock of the lathe off center. Although only two clamping jaws areshowngit will be un derstood that any desired number of jaws may beemployed.

What I claim is A lathe dog comprising a sleeve constructed forengagement with a lathe spindle'and having. a pair of opposing openingsanda collar loosely mounted on the sleeve provided with opposing pinsconstructed to loosely engage the openings in the sleeve, the

collar further being provided with pivotally mounted clamping jaws andan operatingv means therefor. I

In testimony whereof I have afiixed my signature in the presence of twowitnesses. WILLIAM AVERY. Witnesses:

FRIEND P. CARPENTER, Mrs. MINA M. Pnns'ron.

